A tape feeder is often used as a method of supplying electronic components in an electronic component mounting apparatus. A component supply unit provided in an electronic component mounting apparatus is provided with a feeder base, on which a plurality of tape feeders are removably installed, in a form fixedly installed on a base table of a mounting apparatus or disposed on a dedicated cart. A common method of installing a tape feeder on a feeder base is to fit an inverted-T shape fitting part protruded on a lower surface of a tape feeder into a plurality of T-shaped slots juxtaposed in a feeder installing direction on an upper surface of a feeder base (refer to Patent Document 1, for example). In the related art shown in the Patent Document, an installing guide having a T-shaped slot is provided on an upper surface of a feeder base, and a longitudinal member having a T-shaped cross section is disposed on a lower surface of a tape feeder, and a tape feeder is positioned in a longitudinal direction and vertical direction, by fitting a longitudinal member into a T-shaped slot.